Purchased a 40 MY two months ago....

[M___K]

Purchased a 40 MY two months ago. Has twin Cummins QSB 5.9-425 hp engines.   SmartCraft system installed.

Starboard engine above 2600 getting Hogg Intake Manifold Temp alarm. It’s 50 deg higher than port.  Has Aftercooler in perfect shape, new sensor and new raw water impeller.   hoses inspected with endoscope, all perfect, nothing collapsed inside, no build up ( new hoses).

I feel like I’ve spent a ton of time chasing a ghost.  Anyone have similar situation?

I have an appt with Cummins this week, but still love to know what’s going on.

thanks in advance .

[PiscesPearl]

BoatUS magazine has article on similar case that found fouling in intake fitting.

[M___K]

Great suggestion! I forwarded the info to our diver that will look at it. Thank You

[M___K]

Intake fittings all clean underneath.
We took the boat to Jacksonville, FL to have Cummins work on it. It was an expensive diagnostic day.
By afternoon, the mechanic took the hoses off both aftercoolers. I had an endoscope that was used. The mechanic felt the aftercooler cores were different . No guarantee though. I purchased a Cummins OEM core. Eureka that solved the IMT overheat! The previous owner installed an aftermarket core! Now the engines can run at WOT all day if they had to with low IMT temps.

[Pigpen]

Just curious, have you read the articles on aftercoolers on the seaboard marine web site.

[M___K]

Ye I've read everything and every video Seaboard published.

The good news...It's finally fixed ! :)) After and expensive 3 day trip to Jacksonville Fl for Cummins to actually work on the engine, it was solved. Cummins spent an entire day working on it. We did many test runs with various test equipment an laptop plugged into it. We learned that the Turbo outlet air on both engines matched, the boost pressure matched, water flow and pressure through both engines matched. Everything pointed to the after cooler. Using and endoscope the Mechanic pulled both air outlet hoses off the Aftercoolers. His comment:..."...the cores look different ." The differences were extremely subtle. Even if Cummins replaces the core and it does not solve the problem, they would still charge me for the core and labor. The Cummins core was $2,050 I had already romoved the aftercooler and disassembled it twice so what was one more time...save the labor.
I got the Cummins OEM core. I reassembled it as per Tony's video on Seaboard's web site. I used their Alco-MetalLube grease and new O rings. I assumed various brass fittings to pressure test the aftercooler as Seaboard says to do...20 PSI holding for 1 hour. It did. I reinstalled it on the boat and Voila ! Both engines come up to full WOT, both manifold temps match, nice and cool..and the new cooler actually recovers quicker when you throttle back that the port side.

Bottom line, the seller in Savanah, GA lied to me about not having problems. He claimed he never had the problem. NO way! There was no failure of a part. The wrong core or a generic core was installed to save money...it simply did not work.

Thank You for your input.

[Black_Star_line]

So you know about sea ray bow rider 180?

[M___K]

Sorry typo, and it won’t let me correct... HIGH Intake manifold temp... not Hogg ... lol

[M___K]

Bow rider 180... no, don’t know anything about it

[Black_Star_line]

Ok thanks

[M___K]

Mystery solved, previous owner put a “ new “ aftercooler core in it… it was generic, not OEM. Once I installed the Cummins part, it has been perfect ever since.